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3. General information
Compared with simple mechanical thermostats the radio-
controlled radiator thermostat system has a number of ad
vantages:
• the separation into radiator-mounted valve operating
mechanisms and freely positionable operation and con
trol units (e.g. the “FHT8R” heating control which is part
of the scope of supply) makes it possible to perform set
tings easily.
• the programming option makes it possible to adapt the
system to the lifestyle of its users, so that the room is al
ways comfortably warm when it is used. When the room
is not used, the temperature may be reduced automati
cally to save energy, i.e. the often cumbersome manual
opening and closing of heating valves is no longer re
quired.
• The system is equipped with an integrated calcification
protection. Once every week (time can be set) the valve
operating mechanism opens and closes the valve to pre
vent blocking of the valve by lime deposits.
a) Operating principle
In the “FHT8R” heating control the room temperature is
measured and compared to the desired temperature (set ei
ther by means of the time program or manually).
The difference is used to calculate how far the valve has to
be opened or closed to obtain the desired temperature. In
a time interval of approx. two minutes commands are ra
diotransmitted to the “FHT8V” valve operating mechanism
mounted on the radiator. This valve operating mechanism
then reduces or increases the heat.
Heating up of a room takes some time, depending on the
size of the radiators. If the desired temperature is changed,
